1) Field of the Invention
The field of the present invention generally relates to lighting systems and, more particularly, to lighting systems used in transit vehicles or conveyances such as buses, lightrail cars, and the like.
2) Background
Transit vehicles and similar conveyances have historically relied upon fluorescent lighting to provide illumination, in part because of the efficiency of such lighting as compared to, for example, incandescent lighting. However, fluorescent lighting has drawbacks and limitations.
For example, fluorescent lighting has a relatively short lifetime and a high current draw as compared to some other types of lighting The nature of fluorescent lights leads to high electro-magnetic fields, making compatibility with other electrical equipment challenging. Fluorescent lights also often have problems with arcing, which in turn can pose fire dangers or else blow out electrical components and/or cause power ripples. In addition, fluorescent lighting is not very amenable to flexible control, and can be difficult to dim.
Recently, efforts have been made to incorporate light-emitting diode (LED) based lighting within transit vehicles. For example, U.S. Pat. No. 8,400,061, entitled “Control Network for LED-Based Lighting System in a Transit Vehicle” and assigned to the assignee of the present invention, describes a novel transit vehicle lighting system with a plurality of LED-based lighting fixtures for providing interior illumination.
As another interior feature, some transit vehicles or conveyances include a means for displaying information or advertisements to passengers. This may take the form of printed ads mounted to the walls of the transit vehicle, or else may involve electronic displays that can be used to provide information about destinations, advertisements, and the like. Such displays may take the form of an LED matrix for displaying text or simple images or icons, or else may use a liquid crystal display (LCD) to show more detailed moving images in the nature of video.
While message displays or printed advertisements may be useful, there may be insufficient room within the transit vehicle to mount the advertisements or the display mechanism. Providing wall space for these purposes takes away other uses of that space, and for example may limit the size of windows in the transit vehicle. Similarly, lack of adequate interior wall space may result in the message display or advertisements being place in a location within the vehicle that is difficult for passengers to view. In addition, LCD-based displays, while having the advantage of being able to show video, can be expensive and generally require expensive audio-visual electronic components to provide the video (and audio) feeds and store the video information.
It would therefore be advantageous to provide both a means for lighting the interior of a transit vehicle or conveyance and a means for displaying information or advertisements to passengers or others, which overcomes one or more of the disadvantages or limitations of conventional lighting systems, printed advertisements, and/or electronic displays. It would further be advantageous to provide such a means or system which makes efficient use of the interior space of a transit vehicle, and which is generally inexpensive or not overly complex to implement or deploy, and/or has other benefits and advantages not found in the state of the art.